Belt tensioner with pivot bushing

Abstract

A belt tensioner for a power transmission belt is provided that operates on an endless path and that utilizes asymmetric motion control. The belt tensioner has an arm with a belt engaging section and a drum section, a support member for securing the tensioner relative to the belt, where the arm pivots about the support member, and a tension spring that urges the arm to pivot about the support member in a first direction and urges the belt engaging section against the belt with a force to tension the belt. The belt tensioner further comprises a cavity between the arm and the support member and a bushing comprising a bowed flange positioned in the cavity.

What is claimed:  
     
       1. A tensioner for a power transmission belt that operates on an endless path, the tensioner comprising: 
       an arm comprising a belt engaging section and a housing section;  
       a support member for securing the tensioner relative to the belt, the arm pivoting about the support member;  
       a spring that urges the arm to pivot about the support member in a first direction and urges the belt engaging section against the belt with a force to tension the belt;  
       a cavity between the arm and the support member; and  
       a bushing comprising a bowed flange positioned in the cavity wherein the bowing of the flange biases the bushing axially along a longitudinal axis.  
     
     
       2. The tensioner of  claim 1 , the bushing further comprising cutout sections in the bowed flange. 
     
     
       3. The tensioner of  claim 1 , wherein the bushing is made of a nylon material. 
     
     
       4. The tensioner of  claim 1 , wherein the bushing is made of a moldable material. 
     
     
       5. The tensioner of  claim 1 , wherein the bushing has an inner surface comprising a fixed diameter and an outer surface that is tapered. 
     
     
       6. The tensioner of  claim 1 , wherein the spring is a flat, spiral wound spring. 
     
     
       7. The tensioner of  claim 1 , wherein the spring comprises a free wound end. 
     
     
       8. The tensioner of  claim 1 , wherein the support member comprises a housing for the spring. 
     
     
       9. The tensioner of  claim 1 , wherein the support member comprises a hub about which the arm pivots. 
     
     
       10. The tensioner of  claim 1 , wherein the belt engaging section includes a pulley. 
     
     
       11. A method of utilizing a tensioner for a power transmission belt that operates on an endless path, the method comprising the steps of: 
       providing an arm comprising a belt engaging section and a housing section;  
       providing a support member for securing the tensioner relative to the belt, the arm pivoting about the support member;  
       providing a spring that urges the arm to pivot about the support member in a first direction and urges the belt engaging section against the belt with a force to tension the belt;  
       providing a cavity between the arm and the support member; and  
       providing a bushing comprising a bowed flange positioned in the cavity wherein the bowing of the flange biases the bushing axially along a longitudinal axis.  
     
     
       12. The method of  claim 11 , further comprising the step of cutting out sections from the bowed flange. 
     
     
       13. The method of  claim 11 , further comprising the step of making the bushing from a nylon material. 
     
     
       14. The method of  claim 11 , further comprising the steps of making the bushing from a moldable material. 
     
     
       15. The method of  claim 11 , further comprising the step of biasing the bushing axially along its longitudinal axis based on the bowed shape of the flange. 
     
     
       16. The method of  claim 11 , further comprising the steps of forming the bushing with a an inside surface comprising a fixed diameter and an outside surface that is tapered. 
     
     
       17. A tensioner for a power transmission belt that operates on an endless path, the tensioner comprising an arm including a belt engaging section and a housing section, a support member securing the tensioner relative to the belt, the support member comprising a hub having a longitudinal axis and being fixed from movement relative to the belt engaging section, the hub moveably holding the arm, a spring operatively interconnected to the arm and the support member, the spring being configured to urge the belt engaging section relative to the support member and against the belt with a force to tension the belt, the improvement wherein the tensioner further comprises: 
       a cavity between the arm and the support member; and  
       a bushing comprising a bowed flange positioned in the cavity wherein the bowed flange biases the bushing against the arm.  
     
     
       18. The tensioner of  claim 17 , wherein the bushing comprises an inside surface with a fixed diameter and a tapered outer surface.